• The Korean Journal of Food And Nutrition
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• v.9 no.4
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• pp.392-397
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• 1996

To produce low salt fermented anchovy by an accelerated method with Asp. oryzae and Bacillus sp. koji, enzyme activity and variation of microflora during the 60 day fermentation were examined. Bacterial counts changed a little during the fermentation with the highest on day 40 for proteolytic and anaerobic bacteria and on day 20 for aerobic bacteria. Proteolytic, lipolytic, aerobic, and anaerobic bacteria counts were higher in the Bacillus sp. koji added anchovy paste than in others. The protease and lipase activities reached the highest point on day 20 and 30, respectively, and decreased gradually afterwards. The protease activity was higher in Asp. oryzae koji than in bacillus sp. koji, but the lipase activity was to the contrary.

• KSBB Journal
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• v.30 no.1
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• pp.33-37
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• 2015

Recently, several health benefits of rice wine, makgeolli, were known due to the interest on the traditional Korean liquor and the researches on the rice wine are increasing. Organic acids produced during the process of rice wine fermentation play important roles in the taste and flavor. In this study, we have examined the optimal conditions for lactic acid production in rice koji as a carbon source. Skim milk was also used as a supplementary ingredient for the optimization of lactic acid fermentation. Bacterial growth of Lactobacillus sakei was monitored under this condition. The pH, acidity of the culture and the ethanol tolerance of this bacterium were also tested. Through these experiments, we were able to optimize the growth condition of lactic acid bacteria by the addition of skim milk. This was also able to affect the change of pH, acidity, sugar concentration and alcohol tolerance, which might contribute to the improvement of the quality of rice wine. The optimal condition for the growth was 2 days with 10% (w/v) of skim milk concentration. With these results, it was confirmed that rice koji was an effective carbon source for the growth of lactic acid bacteria.

• Korean Journal of Food Science and Technology
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• v.33 no.1
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• pp.94-99
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• 2001

Kochujangs(fermented hot pepper-soybean paste) were prepared either using traditional meju (koji for kochujang) or controlled meju fermented by pure isolates (P-1, P-2), which were screened from traditional meju collected at Sunchang area. The isolates were characterized for their superiority on amylase and protease activities, and overall flavor of the culture on cooked soybean. Bacterial cell counts were not different in all treatments of kochujang during fermentation. The mold counts of each treatment dropped to undetectable level after 40 and 60 days of fermentation, respectively. Heat treatment($60^{\circ}C$, 15 min) before fermentation stopped gas formation and had no effect on bacterial cell count, but the growth of yeast was depressed. Total accumulative volume of gas produced during kochujang fermentation was depended on load of yeast in kochujang and the kochujang using P-2 koji produced least amount of gas among all treatments. The amylase and protease activities of kochujang were not significantly different among traditional and controlled kochujangs.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.1
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• pp.116-124
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• 2010

Bacterial-koji was prepared by using B. subtilis DJI and Doenjang was prepared by using the bacterial-koji and purified salt or solar salt at 12% (w/v) concentration. Characteristics of the Doenjangs were examined after 2 months of aging. Moisture contents of the purified salt-Doenjang was decreased from 51.55% to 45.38% whereas that of the solar salt-Doenjang was decreased from 51.88% to 47.90%. Acidities of the Doenjangs were gradually increased. Hunter's L (lightness) color values of the Doenjangs were decreased. Browning reaction rate of purified salt-Doenjang was faster than solar salt-Doenjang. The content of free amino acids in solar salt-Doenjang was higher than those in purified salt-Doenjang. The major free amino acids of the Doenjang were glutamic acid (252.34 mg%~284.07 mg%), phenylalanine (184.72 mg%~224.71 mg%), leucine, tyrosine and valine.

• Microbiology and Biotechnology Letters
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• v.35 no.4
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• pp.325-333
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• 2007

One bacterium with high proteinase production and spore-forming ability was isolated from korean traditional soybean paste(doenjang). The isolated strain was identified as Bacillus subtilis, based on gram-staining, biochemical properties and l6S rRNA gene sequencing, and designated as B. subtilis DJI. Its growth rate was very fast, and it reached its stationary phase within 9 h, and then started to form spores. Bacterial-koji and doenjang were prepared using B. subtilis DJI. Chemical components of the doenjang were determined after 2 months of aging period: amino nitrogen 507 mg%, crude protein 14.3%, crude fat 4.8% and water 54.9%. The composition of total and free amino acids and their ratios of doenjang were changed during the aging period. Among total amino acids in DJI doenjang, glutamic acid, aspartic acid, leucine and arginine were the major amino acids. The fibrinolytic activities of DJI doenjang and traditional doenjangs were 909.7 units/ml and $363.3{\sim}618.6\;units/ml$, respectively. Flavor compounds of DJI doenjang and traditional doenjang were extracted by SDE(simultaneous steam distillation and extraction), and analyzed by GC/MS; DJI doenjang possessed the typically favorable flavor compounds in traditional korean doenjang, with reduced off-flavor compounds.

• Mycobiology
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• v.50 no.6
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• pp.408-419
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• 2022

Filamentous fungi that could be classified into Aspergillus flavus/oryzae were isolated from traditionally fermented meju commercially available in Korea. The samples were analyzed for aflatoxin B1 and ochratoxin A contamination by HPLC; however, no toxin was detected. In addition, fungal and bacterial metagenomic sequencing were performed to analyze the microbial distribution in the samples. The results revealed that the distribution and abundance of fungi and bacteria differed considerably depending on the production regions and fermentation conditions of the meju samples. Through morphological analysis, ITS region sequencing, and assessment of the aflatoxin-producing ability, a total of 32 A. flavus/oryzae strains were identified. PCR analysis of six regions with a high mutation frequency in the aflatoxin gene cluster (AGC) revealed a total of six types of AGC breaking point patterns. The A. flavus/oryzae strains did not exhibit the high amylase activity detected in the commercial yellow koji strain (starter mold). However, their peptidase and lipase activities were generally higher than that of the koji isolates. We verified the safety of the traditionally fermented meju samples by analyzing the AGC breaking point pattern and the enzyme activities of A. flavus/oryzae strains isolated from the samples. The isolated strains could possibly be used as starter molds for soybean fermentation.

• Asian Journal of Atmospheric Environment
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• v.5 no.3
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• pp.152-156
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• 2011

Viable bacteria on water-insoluble airborne particles were detected in the urban atmosphere of Kumamoto ($134^{\circ}45'E$, $32^{\circ}28'N$), Japan, in autumn 2008. Airborne particles were collected onto film-covered Cu meshes under clear weather conditions. The samples were stained by fluorescent stains, and then viewed and photographed with an epifluorescent microscope. Non-biological and bacterial parts in particles larger than 0.8 ${\mu}m$ were distinguished by their morphologies, fluorescent colors and fluorescent intensities. Bacterial viable statuses were discriminated according to cell membrane damage. In total, 2681 particles were investigated and it was found that 78 airborne particles were associated with bacteria. Viable bacteria were identified on 48 particles. A few particles carried multiple viable bacteria. These results provide the evidence that airborne particles act as carriers of viable bacteria in the atmosphere.

• Microbiology and Biotechnology Letters
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• v.25 no.2
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• pp.203-206
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• 1997

Takju is a traditional alcoholic beverage that has been prepared by fermenting the cooked rice and Nuruk (Korean-style bran koji). During fermentation. bacterial contamination is a problem which inhibits the growth of yeast and thus lowers the ethanol production from starch of rice, and causes souring. Major contaminants were known to be gram-positive acid producers at the early stage of fermentation. This problem would be solved if the contaminated bacteria could be controlled. Nisin, a GRAS-grade preservative, was added at the level of 500 iu/g as it retards the growth of the gram-positive bacteria. It was possible to control acid and ethanol production during fermentation. This process increased the ethanol production by 2 % comparing with control.

• Molecules and Cells
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• v.24 no.3
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• pp.394-408
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• 2007

Several genes/QTLs governing resistance/tolerance to abiotic and biotic stresses have been reported and mapped in rice. A QTL for submergence tolerance was found to be co-located with a major QTL for broad-spectrum bacterial leaf blight (bs-blb) resistance on the long arm of chromosome 5 in indica cultivars FR13A and IET8585. Using the Nipponbare (japonica) and 93-11 (indica) genome sequences, we identified, in silico, candidate genes in the chromosomal region [Kottapalli et al. (2006)]. Transcriptional profiling of FR13A and IET8585 using a rice 22K oligo array validated the above findings. Based on in silico analysis and arraying we observed that both cultivars respond to the above stresses through a common signaling system involving protein kinases, adenosine mono phosphate kinase, leucine rich repeat, PDZ/DHR/GLGF, and response regulator receiver protein. The combined approaches suggest that transcription factor EREBP on long arm of chromosome 5 regulates both submergence tolerance and blb resistance. Pyruvate decarboxylase and alcohol dehydrogenase, co-located in the same region, are candidate downstream genes for submergence tolerance at the seedling stage, and t-snare for bs-blb resistance. We also detected up-regulation of novel defense/stress-related genes including those encoding fumaryl aceto acetate (FAA) hydrolase, scramblase, and galactose oxidase, in response to the imposed stresses.

• Journal of Microbiology and Biotechnology
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• v.27 no.4
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• pp.678-684
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• 2017

The aim of this study was to elucidate the changes in the microbial community and biochemical properties of a traditional sweet paste during fermentation. PCR-denaturing gradient gel electrophoresis (DGGE) analysis showed that Aspergillus oryzae was the predominant species in the koji (the fungal mixture), and the majority of the fungi isolated belonged to two Zygosaccharomyces species in the mash. The bacterial DGGE profiles revealed the presence of Bacillus subtilis during fermentation, and Lactobacillus acidipiscis, Lactobacillus pubuzihii, Lactobacillus sp., Staphylococcus kloosi, and several uncultured bacteria were also detected in the mash after 14 days of main fermentation. Additionally, during main fermentation, amino-type nitrogen and total acid increased gradually to a maximum of $6.77{\pm}0.25g/kg$ and $19.10{\pm}0.58g/kg$ (30 days) respectively, and the concentration of reducing sugar increased to $337.41{\pm}3.99g/kg$ (7 days). The 180-day fermented sweet paste contained $261.46{\pm}19.49g/kg$ reducing sugar and its pH value remained at around 4.65. This study has used the PCR-DGGE technique to demonstrate the microbial community (including bacteria and fungi) in sweet paste and provides useful information (biochemical properties) about the assessment of the quality of sweet paste throughout fermentation.